Evaluation of Chemical and Biological Assays as Indicators of Toxic Metal Bioavailability in SoilsEPA Grant Number: R829418E02
Title: Evaluation of Chemical and Biological Assays as Indicators of Toxic Metal Bioavailability in Soils
Investigators: Pierzynski, G. M.
Current Investigators: Pierzynski, G. M. , Lydy, Michael J. , Schneegurt, Mark
Institution: Kansas State University
Current Institution: Kansas State University , Southern Illinois University - Carbondale , Wichita State University
EPA Project Officer: Chung, Serena
Project Period: September 24, 2001 through September 23, 2003 (Extended to February 23, 2005)
Project Amount: $141,500
RFA: EPSCoR (Experimental Program to Stimulate Competitive Research) (2000) RFA Text | Recipients Lists
Research Category: EPSCoR (The Experimental Program to Stimulate Competitive Research)
Metal contamination is one of the greatest human health risks, particularly to children, and a real threat to ecosystems at every trophic level. We propose to examine a series of biological and chemical assays to compare their effectiveness in adequately including the effects of bioavailability in dose-response assessments. The design of the study will afford an opportunity to compare results from different dose-response assays in soils of known metal concentration and bioavailability level to similar assays with contaminated soils for which we will not have bioavailability information.
The test organisms for the proposed studies will include two plant species, three species of oligochaete worms, and a variety of indigenous and laboratory microbes. Dose-response curves will be generated by observing endpoints having a reasonable expectation of indicating bioavailability. These include mortality, metabolic and growth measures, as well as metal bioaccumulation. Chemical amendments of soil mixtures and added metal salts will be used to generate a range of expected metal availabilities. Comparisons will be made to chemical assays of availability including cation exchange strips and sequential extractions. We also will determine the influence of soil microbial activity on the stability of metal complexes formed by amendment of metal-contaminated soils, as microbes are not only subject to the level of metal bioavailability in soils but can influence the level of metal bioavailability in soils.
Our goal is to determine which of our biological and chemical assays are the most reliable and consistent measures of bioavailability over a range of metal concentrations, metal sources, soil amendments, and availabilities.